In 2023, the Department of Health and Social Care (DHSC) confirmed that “there is no United Kingdom legislation that mandates animal testing”.

For some types of research there is an expectation to use animal experiments, such as the safety testing of new drugs or chemicals – BUT, this is still not required by law.

A common misconception about medical research is that it only involves mice and rats. Whilst mice are the most commonly used animals in research, making up a striking 73% of all animals used in experiments in 2024 – thousands of other animals are also used in British laboratories each year. Animals such as fish, chickens, frogs and rabbits are used, as well as larger animals like dogs, cats, horses, cows, goats and pigs, reflecting the extensive reach of animal research.

In the UK, the Animals (Scientific Procedures) Act 1986 (ASPA) is designed to protect animals in research, but it doesn’t cover every animal or every stage of their life. Invertebrates like fruit flies and worms, which are regularly used in many types of research, are not protected under ASPA – nor are most animal embryos until the final third of their gestation period. This means the true number of animals used each year is likely to be even higher than official reports, as these unprotected animals are not included in the Home Office’s annual statistics.

On 11th November 2025, the Government published its ‘Replacing Animals in Science’ strategy to support the development, validation and use of non-animal alternatives in science. This follows a Labour manifesto commitment to ‘partner with scientists, industry, and civil society as we work towards the phasing out of animal testing.’

While the strategy does include some positive commitments, such as founding a UK Centre for the Validation of Alternative Methods, it does not include a clear timeline, firm targets, or binding legislation to finally end animal experiments, which could mean progress stalls before meaningful change is achieved.

New legislation is needed to accompany and underpin the Government’s strategy, but as this currently is not in place, there is a risk these promises may not be delivered. Herbie’s Law is designed to solve this problem by providing a practical and realistic pathway to help scientists to transition to human-specific methods. It sets a goal of phasing out animal experiments in medical research over the next decade, while working in close collaboration with the scientific community to familiarise and train scientists in the use of alternatives.

Herbie’s Law is essential to ensure that the correct funding, training and support is made available to help researchers use and embrace new methods, and the UK can continue to be a world leader in innovative, and ethical, medical research. Without it, we risk being left behind other countries who have already made ambitious commitments to replace animal experiments in the near future.

So why are millions of animals still used in British laboratories each year?

• Traditional animal-based methods are often seen as the “gold standard” of research, even when newer and more effective alternatives are available. Many methods date back decades, but it’s time to embrace modern technologies to accelerate human science.
• Switching to new, animal-free methods can call for costly upfront investments – labs may need new equipment, training or even a complete overhaul of their systems. Once the switch is made these alternatives are often cheaper and more efficient – it’s a long-term win waiting to happen!
• Confusing regulatory guidelines recommend that new drugs are tested on two species of animals before they can progress to human trials. However, the government has stated that animal experiments are not legally required, and that non-animal data will be accepted instead.

We’re proud to fund pioneering scientists who are breaking barriers and leading the way in ethical, human-specific science. Their work isn’t just transforming research – it’s saving lives and shaping a future free from animal suffering.

Animal experiments have been considered the “gold standard” for drug development for decades. Regulatory requirements even mandate testing on two species – typically a small animal like a mouse and a larger one such as a dog – before human clinical trials.

But, the reality is that animals are biologically different from humans, which often leads to unreliable results. Shockingly, over 92% of drugs that pass animal tests fail in humans – either before they’re unsafe or ineffective.

Innovative, animal free New Approach Methodologies (NAMs) like organ-on-a-chip, lab-grown human tissues and advanced computer models are revolutionising the way we test medicines, without the use of animals. These technologies are human-specific, accurately mimicking the way human cells and organs behave, while being more accurate in predicting how a drug interacts with the human body than an animal.

Animal experiments account for a large proportion of medical research, yet we are no closer to curing many of the world’s most common and debilitating diseases, such as cancer and Alzheimer’s disease. Many diseases are uniquely human, so using animals to study them often leads to misleading results.

Positive results in animal experiments have even led to unsafe treatments being tested in humans with devastating outcomes. Over 92% of drugs fail during human clinical trials, while Alzheimer’s disease drugs have a staggering 99.6% failure rate, despite promising results in animal tests. Animals like monkeys don’t naturally develop Alzheimer’s, or live long enough to study ageing in the same way that humans experience it, so these outdated methods are simply not giving us the answers we need.

But there is hope. Herbie’s Law supports scientists to transition to innovative, human-specific technologies over a ‘decade of change’. It’s time to redirect our energy into new methods, moving away from outdated and unethical practices to give hope for the questions that decades of animal experiments have already failed to answer.

Animal experiments have long been the “gold standard” in medical research. But today, innovative animal-free technologies are proving that animal research may not be the most effective approach.

Some people claim that stopping animal experiments would mean an end to research into diseases like cancer, dementia, asthma or diabetes. But this simply isn’t true – the future of research won’t stop, it will evolve.

Animal experiments are failing to deliver the breakthroughs we urgently need for patients. Many diseases are unique to humans and don’t naturally occur in animals, so to compensate, animals are often genetically modified to mimic disease symptoms. However, even with these modifications, animals rarely develop the full spectrum of symptoms experienced by humans.

Animals are not miniature humans: our biology, anatomy and genetics are  very different. But the good news is that thanks to cutting-edge, human-specific technologies like organ-on-a-chip systems and advanced computer modelling, we can now study diseases with a precision and relevance never before possible.

Over the years, animal-to-human transplants have been trialled as a solution for various human diseases, but this process is risky, unreliable and raises serious ethical and scientific concerns. Two genetically modified pig-to-human heart transplants have recently been attempted, but there are still many obstacles to overcome:

• High rejection rates – Our immune system attacks foreign tissue, even with heavy immunosuppressive drugs
• Infection risks – Pigs carry viruses that could pose serious health risks to patients
• Limited success – Past attempts have sadly ended in early death
• Ethical issues – Breeding and genetically modifying animals for ‘spare parts’ raises serious ethical concerns

Instead of looking to animals, the future lies in cutting-edge, human-relevant technologies like lab grown human tissue for personalised medicine, and stem cell therapies and 3D bioprinting to regenerate damaged heart tissue. These examples show that human-specific science can save lives without harming animals.

Did you know that researchers need a licence to experiment on animals? At the end of 2024, 2,315 project licences and 13,311 personal licences were active in British labs, permitting experiments on a specific number of animals in a particular place.

But here’s the shocking truth:

• 146 cases of non-compliance were reported in just one year.
• 22,204 animals were affected.
• 189 animals suffered more pain and distress than legally allowed.
• 37% of breaches were due to a failure to provide basic care.
• 9 cases were due to ‘failure to provide food and water’ – in some cases for up to 5 days.

The Animals in Science Regulation Unit (ASRU) report makes it clear that the only way to truly prevent animal suffering in laboratories is to prevent them from being there in the first place. Herbie’s Law can change this. By accelerating the transition to modern, animal-free technologies, we can remove animals from laboratories for good.

We’ve witnessed incredible technological progress over the past few decades, from mobile phones and artificial intelligence to robotics and medical advancements that once seemed impossible. 20 years ago, today’s technology was unimaginable – so why should we assume animal-free research wont’ follow the same trajectory?

With the right investment and prioritisation, ground-breaking animal-free methods like organ-on-chip and complex computer models will continue to evolve and outshine outdated, unreliable animal experiments.

In fact, these technologies are already proving to be more accurate, reliable and cost-effective than testing on animals. Yet, they remain underutilised.

Simply put – we are stuck in a rut. A mindset shift is desperately needed: one that embraces innovation and recognises that human-specific specific science is not just the future – it’s the best way forward.

Herbie’s Law will empower scientists to move away from animal testing by prioritising:

• Retraining researchers in cutting-edge, human-specific methods.
• Investing in innovative, animal-free technologies to ensure they continue to evolve.
• Encouraging collaboration between policymakers, scientists and industry professionals.

By revolutionising how research is conducted in Britain, Herbie’s Law will ensure that science focusses on human-specific results that directly benefit patients – without harming animals in the process.

It’s time to break free from outdated, unreliable research and champion a future where science works for humans and animals alike.

Switching to animal-free research methods can feel like a big step for scientists who have relied on traditional animal experiments for years. Some worry that adopting modern, human-specific techniques will be too expensive. But while there may be upfront costs for new equipment or training, these innovative methods are often more cost-effective in the long run.

Here’s why:

• Faster results: Traditional animal experiments can take months or even years. Cutting-edge technologies like organ-on-a-chip, artificial intelligence-driven drug screening and 3D bioprinting generate results faster, saving time and money.
• More reliable data: Around 92% of drugs that pass animal tests fail in human trials, leading to billions wasted in research and development. Human-specific models reduce costly failures and improve success rates.
• Lower maintenance costs: Housing, feeding, breeding and providing veterinary care for animals in laboratories is extremely expensive. In contrast, lab-based and computational models eliminate these ongoing costs.
• Less waste: When animal-based methods fail to translate to humans, researchers often need to repeat experiments, wasting valuable time and resources. Human-specific research gives clinically relevant results the first time.

This is why investing in animal-free research isn’t just the ethical choice – it’s the smart, economical and forward-thinking choice.

So the real question is: can we afford not to transition?

The forced swim test, first developed in the 1970s, is an experiment where mice or rats are dropped into an inescapable chamber of water and are forced to swim to stop themselves from drowning. The experiment is timed to see how long the animals will struggle for before they give up and stop swimming.

This measure of “despair” is used as a way to test antidepressant drugs, where the amount of time the animals continue to struggle is thought to relate to their mental state. The longer they struggle, the more they want to live – showing if the antidepressive drug is effective or not.

Animals can be subjected to this test several times over different days, and after the experiments are finished they are usually killed so their brains can be studied.

But the truth about the forced swim test is:

• It is not an accurate model of human depression.
• It hasn’t led to better treatments.
• It is unreliable, and results can be interpreted in different ways.
• It causes intense stress and suffering.

But there is some good news: Bristol and Bath Universities have recently become the latest UK institutions to ban the forced swim test – a win for animals and science – but this, and other unreliable tests continue elsewhere, with 250 instances of its use in British labs reported in the 2024 Home Office statistics.

Over 300 million people worldwide are estimated to suffer with depression. Mental health research deserves better and more ethical alternatives that will truly benefit patients and save animal lives.

Before a new drug reaches human trials, it must be tested on at least two animal species. But here’s the shocking reality: over 92% of drugs that pass these tests fail in human trials – and even those that do make it to market aren’t always safe.

Since 1953, over 400 drugs have been withdrawn from the global market – the most common cause? Severe liver toxicity that animal tests failed to predict, which can lead to drug-induced liver injury (DILI) – a serious and sometimes fatal condition.

So, why do drugs that pass animal tests still harm humans? The simple reason is that animals aren’t people. Their biology is different, meaning dangerous side effects can go unnoticed until human trials – or worse, when the drug is already in use by vulnerable patients.

History has shown us the deadly consequences of relying on animal tests:

• Thalidomide – Deemed safe in animals, this drug caused severe birth defects in thousands of babies.
• Vioxx – A painkiller linked to thousands of heart attacks and deaths.
• Avandia – A diabetes drug that increased the risk of heart failure in humans.
• Propulsid – Heartburn medication withdrawn due to fatal heart complications.

Innovative animal-free technologies like organ-on-a-chip, artificial intelligence (AI) and complex human cell culture can replace animal tests with more accurate, ethical and effective ways to test new drugs – helping to ensure that drugs will actually help patients, rather than cause harm.

Testing of cosmetics on animals has been banned in the UK since 1998, but did you know that thousands of animals are still used to test chemicals and household products every year? Even though guidelines state that non-animal data can be accepted instead of animal experiments, in 2024, over 80,000 animals including mice, rats, dogs, rabbits and fish, were used in regulatory toxicity testing of industrial chemicals, pesticides and food contact materials (a 23.5% increase compared to 2023).

These tests can involve:

• • Forcing animals to inhale toxic fumes
  • Applying chemicals to their skin or eyes
  • Feeding them substances to check for poisoning

This isn’t just outdated – it’s unnecessary and unreliable.

Animal tests don’t always predict human reactions, leading to unsafe chemicals reaching the market and delays in banning harmful substances. Advanced, animal-free technologies like organ-on-a-chip, complex cell culture, and AI-driven toxicity screening can be used to replace animal experiments, providing safer, more accurate results without suffering.

It’s time to end ALL animal testing – not just in medical research, but across all industries, for a brighter future for humans and animals.

The UK’s Animal Welfare (Sentience) Act 2022 acknowledges that vertebrates and some invertebrates are sentient – meaning they can experience pain, distress, and emotions.

The UK even extended legal protections under the Animals (Scientific Procedures) Act (ASPA) to cephalopods (like octopuses and squid), because research confirmed their ability to feel pain and suffer.

Yet, despite this recognition, millions of sentient animals – including dogs, cats, rabbits, and even highly intelligent primates – are still subjected to stressful and painful experiments every year in the UK.

Examples of painful and stressful experiments can include:

• Surgery to incapacitate animals’ limbs to mimic muscle wasting diseases.
• Toxicity tests where animals are force-fed drugs or chemicals until they suffer organ failure or die.
• Brain implants that cause distress and confusion.

We wouldn’t subject humans to this treatment, so why should animals suffer instead? Animals are intelligent, self-aware, and have been proven to feel pain and emotions, so we need to do better by them.

It’s time to replace animals with modern, human-specific methods that provide accurate and reliable results to benefit medical research, while sparing animals from suffering.

Many antibiotics that pass animal tests fail in humans – either because they don’t work, or they cause unexpected harm. Bacteria behave differently in animals than in humans, meaning that antibiotics could be more or less effective, and toxicity tests may not be accurate, resulting in dangerous side effects in humans.

In the past, several antibiotics have caused toxicity and effects in humans after being found safe in animal testing, such as Telithromycin which can cause severe liver damage in humans, and Chloramphenicol, which can cause fatal bone marrow suppression.

Some antibiotics that we now use daily, such as Penicillin, were almost lost because of unreliable animal tests. This commonly used life-saving antibiotic failed in rabbits because their bodies broke it down too quickly. Human trials ultimately confirmed that penicillin was a promising antibiotic for bacterial infections – but had scientists relied on the animal test results, this life-saving drug might never have been developed.

Penicillin’s failure in rabbits shows why animal testing is unreliable for predicting how drugs will work in humans. Modern human-based research methods like organ-on-a-chip and 3D cell cultures provide more accurate results without risking the loss of life-saving treatments.

It’s time to move beyond outdated and unreliable animal tests and invest in science that truly works for humans!

It’s a common misconception that all animals used in British laboratories are bred here, in Great Britain. In reality, the picture is much bigger – and far more troubling.

Every year, thousands of animals are imported into Britain to be used in scientific research. Among them are monkeys, who are flown in from Africa and Asia. These journeys often involve long hours, or sometimes days, of travel, often in cramped conditions, noisy cargo holds and unfamiliar environments. The result is a huge amount of stress and suffering for these animals, before they’ve even reached the lab.

This global supply chain raises serious ethical concerns, yet in 2024, 1,326 monkeys were imported from Africa and Asia for use in British labs. These intelligent, sensitive animals are often taken from breeding centres with unclear welfare standards, before they are subjected to gruelling transportation that can leave them traumatised and in poor health.

We can – and must – do better. By investing in advanced, human-specific research methods, we can reduce our reliance on animals, improve scientific outcomes and create a more ethical, sustainable future for research.

Following the release of the Government’s Replacing Animals in Science Strategy, some have claimed that if we phase out animal experimentation in Britain, animal tests will not end, but instead will be ‘outsourced’ to other countries which have lower welfare standards and less robust laws to protect animals.

However, other countries have already made greater, more specific commitments to develop and implement non-animal technologies – potentially leaving Britain behind.

In the USA, the FDA has launched a plan to ‘make animal studies the exception rather than the norm for preclinical safety/toxicity testing’ within the next 3-5 years. The FDA has also issued new guidance to outline specific product types for which it believes six-month non-human primate toxicity testing can be reduced or eliminated.

The Netherlands is heavily investing in its Centre for Animal-Free Biomedical Translation, which aims to accelerate the transition of new biomedical innovations to patients at lower costs and without the use of animals. The Netherlands has also recently voted to redirect funding away from experiments on non-human primates at the Biomedical Primate Research Centre (the largest non-human primate lab in their country) and towards human-specific technologies.

The European Union is due to publish its roadmap to phase out chemical testing on animals shortly. The EU has also just published its plans for a European Biotech Act which will accelerate the development of innovative new treatments and therapies for patients.

While the Government’s strategy is a positive first step towards change in British labs, other countries have made more ambitious commitments. Without implementing Herbie’s Law, Britain could be left behind as rather than seeking other countries to carry out animal research, so the greater risk is losing our best researchers to other nations who are heavily investing in human-specific research.

Here’s why relying on animals doesn’t work:

• Mice are around 3000 times smaller than humans, but their metabolism is 7 times faster than ours. This means their ageing, drug processing, and immune systems are very different from ours, making results unreliable.
• 92% of drugs fail in human clinical trials following animal tests. Positive results from animal tests can’t guarantee that a drug will be safe for patients, and has led to some catastrophic incidents in human clinical trials in the past.
• Animals are used in research because of their genetic similarity to humans – yet while we share up to 98% of our DNA with some animals, it’s the small yet important differences that make us distinct. Many diseases like Alzheimer’s and HIV are unique to humans, meaning animals cannot truly replicate them, even with genetic modifications.

For these reasons and many more, human-specific research is our best path to discovering new and effective treatments for human diseases.